EXHIBIT 99.1





Company contacts:
Advanced Magnetics, Inc.                  Cytogen Corporation
Jerome Goldstein, CEO                     Michael Becker, CEO
  or Lisa Gordon, Investor Relations        or Stacy Shearer, Investor Relations
 (617) 497-2070                           (609) 750-8289


        PRESENTATIONS AT ISMRM SUGGEST COMBIDEX(R)USEFUL IN DETECTING THE
              SPREAD OF BREAST AND PROSTATE CANCERS TO LYMPH NODES

CAMBRIDGE, MA, AND PRINCETON, NJ (JULY 15, 2003) - Advanced Magnetics, Inc.
(AMEX: AVM) and Cytogen Corporation (NASDAQ: CYTO) today announced data showing
that magnetic resonance imaging (MRI) with Combidex(R) (ferumoxtran-10), an
investigational iron oxide nanoparticle, aids in the non-invasive diagnosis of
metastatic lymph nodes. The data presented at the International Society for
Magnetic Resonance in Medicine (ISMRM) 11th Scientific Meeting held in Toronto,
July 10-16, 2003 was from a study that included patients with breast and
prostate cancer.

One presentation entitled "Detection of Minimal Nodal Disease in Patients with
Breast Cancer," was made by Dr. Mukesh Harisinghani, Assistant Radiologist at
Massachusetts General Hospital. Dr. Harisinghani concluded that
Combidex-enhanced MRI is a useful tool for characterizing lymph nodes in
patients with breast cancer. Dr. Harisinghani also noted that one of the
patients analyzed in this presentation was determined to be free of metastatic
disease based on sentinel node mapping and biopsy of the sentinel node but that
another lymph node was determined to be metastatic based on Combidex-enhanced
imaging. This second node was confirmed to be metastatic after removal at
surgery.

A second presentation on data from prostate cancer patients was made by Dr.
Ralph Weissleder, Director of the Center for Molecular Imaging Research at
Massachusetts General Hospital. Dr. Weissleder concluded that Combidex is a
useful MRI contrast agent for characterizing lymph nodes in patients with
prostate cancer, and that Combidex-enhanced images alone may suffice for lymph
node characterization.

"The data presented here show the potential role that Combidex-enhanced imaging
could have in the diagnosis of lymph node metastases," stated Jerome Goldstein,
Chairman and Chief Executive Officer of Advanced Magnetics. "The results coming
from Dr. Harisinghani's group at Massachusetts General Hospital have
consistently shown the advantages that Combidex could have in assisting
physicians in staging cancer patients. We continue to be encouraged by these
results."

"Both of the presentations made at ISMRM build on the data we have seen for
Combidex in a number of cancers that spread to the lymph nodes," said Michael
Becker, President and Chief Executive Officer of Cytogen Corporation, which has
exclusive U.S. marketing rights to Combidex. "This growing body of scientific
data supports our belief that Combidex could be an important new tool for
physicians and their patients in staging a variety of cancers."


Combidex, the lead product in Advanced Magnetics' development pipeline, received
an approvable letter, subject to certain conditions, from the U.S. Food and Drug
Administration (FDA) for use in the diagnosis of metastatic lymph nodes.
Advanced Magnetics continues to work with the FDA to resolve the outstanding
issues from the approvable letter in an effort to bring Combidex to the market.

ABOUT ADVANCED MAGNETICS, INC.

Advanced Magnetics, Inc. is the premier developer of superparamagnetic iron
oxide nanoparticles used in pharmaceutical products. As a leader in its field,
Advanced Magnetics is dedicated to the development and commercialization of its
proprietary nanoparticle technology for use in therapeutic iron compounds to
treat anemia, as well as novel imaging agents to aid in the diagnosis of
cardiovascular disease and cancer. For more information about Advanced
Magnetics, please visit the company's website at www.advancedmagnetics.com,
which is not part of this press release.

ABOUT CYTOGEN CORPORATION

Cytogen Corporation of Princeton, NJ is a product-driven, oncology-focused
biopharmaceutical company. Cytogen markets proprietary and licensed oncology
products through its in-house specialty sales force: ProstaScint(R) (a
monoclonal antibody-based imaging agent used to image the extent and spread of
prostate cancer) and NMP22(R) BladderChek(TM) (a point-of-care, in vitro
diagnostic test for bladder cancer). Cytogen has also developed Quadramet(R), a
skeletal targeting therapeutic radiopharmaceutical for the relief of bone pain
in prostate and other types of cancer. Cytogen has exclusive U.S. marketing
rights to Combidex(R), an ultrasmall superparamagnetic iron oxide contrast agent
for magnetic resonance imaging of lymph nodes. Cytogen's pipeline comprises
product candidates at various stages of clinical development, including fully
human monoclonal antibodies and cancer vaccines based on PSMA (prostate specific
membrane antigen) technology, which was exclusively licensed from Memorial
Sloan-Kettering Cancer Center. Cytogen also conducts research in cell signaling
through its AxCell Biosciences research division in Newtown, PA. For more
information, please visit the company's website at www.cytogen.com, which is not
part of this press release.

FOR ADVANCED MAGNETICS:

This document contains forward-looking statements. Any statements contained in
this press release that do not describe historical facts are forward-looking
statements that involve risks and uncertainties that could cause actual results
to differ materially from those discussed in such forward-looking statements.
Such risks and uncertainties include the following: uncertainties relating to
Advanced Magnetics' ability to resolve the outstanding issues from the
approvable letter received from the FDA for Combidex and to resolve final
labeling for Combidex with the FDA, the timing and outcomes of FDA actions
regarding Combidex, uncertainties regarding market acceptance of Combidex,
uncertainties relating to third-party reimbursements, uncertainties relating to
Advanced Magnetics' ability to continue to operate at commercial scale in
compliance with FDA regulations and other applicable manufacturing requirements,
uncertainties relating to patents and proprietary rights and other risks
identified in Advanced Magnetics, Inc.'s Securities and Exchange Commission
filings. Advanced Magnetics cautions readers not to place undue reliance on any
forward-looking statements which speak only as of the date they are made.
Advanced Magnetics disclaims any obligation to publicly update or revise any
such statements to reflect any change in expectations or in events, conditions
or circumstances on which any such statements may be based, or that may affect
the likelihood that actual results will differ from those set forth in the
forward-looking statements. The data described herein is not part of the FDA's
review of Combidex.


FOR CYTOGEN:

This press release contains certain "forward-looking" statements within the
meaning of the Private Securities Litigation Reform Act of 1995 and Section 21E
of the Securities Exchange Act of 1934, as amended. All statements, other than
statements of historical facts, included in this press release regarding our
strategy, future operations, financial position, future revenues, projected
costs, prospects, plans and objectives of management are forward-looking
statements. The words "anticipates," "believes," "estimates," "expects,"
"intends," "may," "plans," "projects," "will," "would" and similar expressions
are intended to identify forward-looking statements, although not all
forward-looking statements contain these identifying words. Such forward-looking
statements involve a number of risks and uncertainties and investors are
cautioned not to put any undue reliance on any forward-looking statement. There
are a number of important factors that could cause Cytogen's results to differ
materially from those indicated by such forward-looking statements. In
particular, Cytogen's business is subject to a number of significant risks,
which include, but are not limited to, the risk of obtaining the necessary
regulatory approvals, the risk of whether products result from development
activities, the risk of shifts in the regulatory environment affecting sales of
Cytogen's products such as third-party payor reimbursement issues, and the risk
associated with Cytogen's dependence on its partners for development of certain
projects. Cytogen cannot guarantee that Cytogen will actually achieve the plans,
intentions or expectations disclosed in any such forward-looking statements.
Cytogen's actual results may differ materially from Cytogen's historical results
of operations and those discussed in such forward-looking statements and the
risks stated above for various reasons, including, but not limited to, Cytogen's
ability to carry out its business and financial plans, to successfully
commercialize QUADRAMET(R), to determine and implement the appropriate strategic
initiative for its AxCell Biosciences subsidiary, to fund development necessary
for existing products and to pursue new product opportunities, to integrate
in-licensed products such as NMP22(R) BladderChek(TM), to establish and
successfully complete clinical trials where required for product approval, to
obtain foreign regulatory approvals for products and to establish marketing
arrangements in countries where approval is obtained, and other factors
discussed in Cytogen's Form 10-K for the year ended December 31, 2002, as
amended, and from time-to-time in Cytogen's other filings with the Securities
and Exchange Commission. Any forward-looking statements made by Cytogen do not
reflect the potential impact of any future acquisitions, mergers, dispositions,
joint ventures or investments Cytogen may make. Cytogen does not assume, and
specifically disclaims, any obligation to update any forward-looking statements,
and these statements represent Cytogen's current outlook only as of the date
given.

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